N-hydrocarboyl phosphoroamidothioates and phosphoroamidodithioates (referred to herein as “phosphoroamido(di)thioates”) are classes of systemic insecticides that are used in a variety of environments. One of the most commercially important compounds within this class is acephate. Acephate and related compounds are described in U.S. Pat. Nos. 3,716,600, 3,845,172 and 3,914,417. Orthene® is a commercial form of acephate that is produced as a technical grade chemical of about 97 to 99.5% purity. It is available as a liquid and fine powder.
Golf courses and other grassy public areas use acephate to control insects within the grass. The acephate is often applied as a wettable powder or, more recently, as a granule. It is very effective and economical.
Unfortunately, acephate insecticides like sulfur-bearing solid and aromatic solvent-containing liquid agrichemicals can leave an unpleasant, objectionable odor in the treated area. This odor introduces restrictions on the times when the composition can be applied in areas frequented by members of the public.
In past attempts, those in the art have tried to formulate phosphoroamido(di)thioate and other agrichemical compositions with a wide variety of materials to solve the odor problem. None has been commercially viable. One reason for the lack of success with the phosphoroamido(di)thioates is a notorious instability against hydrolysis from residual moisture in a solid formulation and from exposure to elevated temperatures during manufacture, shipment, or storage. The pH of many perfumes and odor reducing agents may also degrade the active ingredient of a formulation after extended storage or exposure to elevated temperatures.
It would be desirable to have a solid composition containing an agriculturally effective phosphoroamido(di)thioate and an odor masking agent that would reduce perception of an objectionable odor in and around an area treated with the phosphoroamido(di)thioate without adversely affecting the stability of the phosphoroamido(di)thioate molecule or its insecticidal efficacy.
It would also be helpful and commercially advantageous to have an agrichemical formulation for sulfur-bearing solid and liquid agrichemicals that hid or masked objectionable odors from human perception in an area treated with the agrichemical without adversely affecting the efficacy of the agrichemically active ingredient.